RU2553938C2 - Catheter pump - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: group of inventions refers to medicine and can be used for temporary blood supply maintenance. A catheter pump comprises an elongated sleeve with a drive rod passing through the sleeve and having its proximal end attached to an outer driven energy source. A rotor is mounted at the side of the distal end of the drive rod on a drive shaft connected to the drive rod, and represents a propeller encaged by ribbons, threads or strips. Ends of the above grouped ribbons, threads or strips are fastened on mutually movable tubes found on the drive shaft. The propeller and the cage are configured so as to transform from the folded position corresponding to the drive shaft attachment into the unfolded working position. A rotor fixation unit inserted into the ascending part of the aorta in a proximity to the aortic valve is formed by an element projecting from the distal end of the catheter and inserted into the heart for the purpose of using its wall as a support. The length of the projecting element is so that when its distal end rests against the heart wall, the propeller and cage are found outside the heart, however within the ascending portion of the aorta in proximity to the aortic valve. There are disclosed alternative embodiments of the catheter pump having features of construction.

EFFECT: invention enables providing higher performance with minimally invasive intervention for the pump implantation.

6 cl, 12 dwg

Description

State of the art

The Reitan Catheter Pump System (″ The Reitan Catheter Pump System ″) is a temporary circulatory support system based on the concept of a folding propeller attached to the end of a flexible catheter. The system is intended for patients with heart failure, when the heart is not able to supply the body with enough oxygen-enriched blood.

This system is described in EP 0768900 and in Swedish patent applications 0801459-9 and 0801460-7, and the information contained in the mentioned publications about the system, taking into account its latest improvements, are incorporated by reference into this description. The dimensions given in these documents are preferred, i.e. do not impose restrictions on the scope of the invention.

Several blood pump models are available for sale. However, implantation of most of them requires serious surgical intervention. Therefore, the use of a folding propeller has the advantage that its introduction in the folded state allows you to insert a large propeller percutaneously into the body, without the need for surgical intervention. When deployed, a large pump propeller provides high performance. The propeller is placed in the pump head at the distal end of the catheter. In addition to the propeller, the pump head also contains a cage made of threads surrounding the propeller to protect the aorta from it.

The introduction is performed percutaneously, by puncture of the arterial system, preferably the femoral artery in the inguinal region, through the "sleeve" of the introducer. The previous version of the pump advanced into the upper part of the thoracic aorta so that the pump head was approximately 5-10 cm below the left subclavian artery. Having installed the pump in a predetermined position, the propeller and its protective cell are opened from the proximal end of the flexible catheter by means of an umbrella-type mechanism. In this position, the rotation of the propeller creates a pressure gradient inside the aorta. Lowering the blood pressure created in the upper part of the aorta facilitates the expulsion of blood from the left ventricle. Elevated pressure in the lower part of the aorta facilitates perfusion of internal organs, especially the kidneys.

Energy is transferred to the propeller using a rotating drive rod passing through the inside of the catheter and connected at the proximal end to a DC motor. This engine is capable of operating at an adjustable speed of rotation controlled by a specially designed control panel.

The CARDIOBRIDGE REITAN system consists of four main components: 1 - a catheter with a pump head, 2 - a drive module, 3 - a control panel and 4 - a flushing kit.

The REITAN catheter pump itself contains flexible external and internal catheters that can slide and slide in order to open the protective cage and deploy the propeller inside it. A flexible drive shaft extends through the central lumen of the internal catheter. The internal catheter also has two small channels for transporting a twenty percent glucose solution to the pump head for lubrication and flushing. One third of the solution returns through the central lumen for the drive shaft, and two thirds enter the patient.

Pump head

The diameter of the pump head mounted at the distal end of the flexible catheter when inserted is about 3.5 mm (10 French), while its deployed size is about 19.5 mm. The propeller is rotated by means of a rotating drive rod, which extends along the central lumen of the internal catheter, starting from its proximal end, coupled through a magnetic field to a DC motor located in the drive module.

Drive module

The drive module is designed to be placed next to the patient’s bed and is equipped with a leading magnetic coupling half for connecting one end to a catheter pump. The other end of the drive module is connected by an electric cable to the control panel.

Remote Control

The main functions of this console are to monitor and control the speeds of the catheter pump and peristaltic pump for flushing fluid. All system management functions and monitored parameters are displayed on the touch screen (touchscreen).

The speed of rotation of the engine, the rotating drive rod and the propeller is regulated and controlled by the control panel. The adjustment range is 1000-15000 rpm.

Flushing system

The flushing system is used to lubricate the rotating parts of the pump and to prevent blood from entering them. It consists of small channels formed inside the catheter to transport a sterile twenty percent glucose solution to lubricate the internal components. Heparin is added to the flushing fluid. One third of the fluid is transported back through the inner lumen and lubricates the rotating drive shaft. Two thirds of the glucose solution enter the patient’s circulatory system, separating it from the drive shaft. The speed of the peristaltic pump is set from the control panel.

The described system is disclosed in document WO 2009/157840 published after the priority date of the present invention.

Next will be described the improvements considered catheter pump.

The described construction lacks a locking mechanism for safe positioning and fixation of the pump in the ascending aorta (above the aortic valve) when the pump is inserted into the patient’s body in the inguinal region.

The following problems are associated with the introduction through the femoral artery:

the pump must be drawn through a bend formed by the aortic arch;

it is necessary to fix the pump in the ascending part of the aorta in order to eliminate the danger of its displacement before touching the aortic valve.

However, modern pumps can be placed in the ascending part of the aorta during heart surgery only through a shunt on the aortic arch or, in some cases, through the right (or left) carotid artery.

No. 4,753,221 describes an elongated blood pump catheter. This catheter contains elastic fingers for stopping radially outward into the walls of the pulmonary artery and for holding the catheter at a distance from the inner walls of the aorta, so that blood can flow freely into the coronary arteries.

EP 0364293 A2 describes a blood pump catheter comprising an annular barrier wall serving to hold the distal end of the catheter in a desired functional position within the aorta.

DE 10336902 B3 describes an intracardiac transdermal pump device comprising a pump connected to the proximal end of the catheter, which is connected to the cannula from the distal end (suction side), the inlet openings of which are spatially remote from the pump. A flexible element protrudes from the distal end (inlet) of the cannula, which can be equipped with a “pork tail” used in catheters and stents. The rounded “pork tail” serves as an atraumatic support on the tissue of the heart or vessel wall.

Disclosure of invention

The invention is directed to the creation of a pump head, which can be advanced further into the aorta, with passage through the aortic arch to the ascending aorta.

To solve this problem, options are proposed for a catheter pump for positioning in the ascending aorta near the aortic valve of a human patient, forming a single inventive concept.

The first embodiment of the catheter pump contains an elongated sleeve with a drive rod passing through the sleeve and connected by its proximal end to an external source of drive energy, and a rotor that is mounted, from the side of the distal end of the drive rod, on the drive shaft connected to the drive rod, and is caged propeller. The ends of the group of said tapes, threads or strips are fixed on mutually movable tubes located on the drive shaft, and the propeller and cage are made with the possibility of deployment from the folded position corresponding to the abutment to the drive shaft to the deployed, working position. This position is characterized by the fact that it additionally contains means for fixing the rotor, after its introduction, in the ascending part of the aorta near the aortic valve, which is formed by an element protruding from the distal end of the catheter and intended to be inserted into the heart in order to use its wall as a support. In this case, the length of the protruding element is chosen such that, when the distal end stops in the heart wall, the propeller and cell are outside the heart, but in the ascending part of the aorta near the aortic valve.

The second version of the catheter pump differs from the first in that the element protruding from the distal end of the catheter and forming the rotor fixation means, in its natural state, has the shape of a ring, part of a ring or spiral, located (located) in a plane perpendicular to the longitudinal axis of the catheter, but made with the possibility of introducing, in a straightened state, into a blood vessel and returning to a natural state outside the heart near it with maintaining the rotor and placing around the rotor above the aortic valve in that the distal end, the terminating distal end of the projecting member is located in the wall or against the wall of the ascending aorta.

The third variant of the catheter pump differs from the first and second variants in that in it some of the tapes, threads or strips forming the cell, or parts thereof, are configured to protrude from the cell in order to contact their distal ends with the wall of the blood vessel and fix the cell with the prisoner in it a rotor in the ascending aorta near the aortic valve.

Moreover, in any of these pump options, the tapes, threads or strips of the cell can form an open structure that allows the formation of retrograde blood flow outside the rotor.

The placement of a catheter pump in the ascending aorta provides significant benefits.

Retrograde blood flow, aortic valve, and coronary perfusion

When the pump is placed in the tube (aorta), the rotation of the propeller creates a pressure gradient inside the tube, i.e. the pressure before the propeller will be lower than behind it. The pressure gradient creates retrograde blood flow along the tube wall. Since the blood flow along the aortic wall is directed against the blood flow through the propeller, it can be considered as leading to energy loss.

The aortic valve is a three-petalled valve attached to the wall of the ascending aorta, directly above the left ventricle. If the pump is installed above the aortic valve, retrograde blood flow is stopped by the valve petals. Thereby, the effect of increasing the pressure gradient is achieved.

In laboratory tests, the pressure could increase by more than 3 times compared with the pressure provided in a straight tube.

Due to this, the following results are provided:

1) the afterload of the left ventricle is reduced, which means a decrease in the workload on this ventricle;

2) since the coronary arteries extend above the valve petals, an increase in retrograde blood flow will increase the pressure of coronary perfusion;

3) positioning the pump to the point of departure of the cerebral arteries will enhance brain perfusion.

The catheter is preferably inserted via a puncture of the arterial system, preferably a puncture of the femoral artery in the inguinal region, through the “sleeve” of the introducer. Then a catheter pump is inserted, which is fixed in a predetermined position in the ascending part of the aorta, directly above the aortic valve. When used, the pump forms a series circuit with the heart.

Brief Description of the Drawings

The invention will now be described in more detail with reference to the accompanying drawings.

In FIG. 1-3, a first embodiment of the invention is presented in which the pump head is fixed by means of a protruding element intended for its introduction into the heart.

In FIG. Figures 4-6 show a second embodiment of the invention in which the pump head is fixed by means of a protruding catheter element, which should be located outside the aortic valve.

In FIG. 7 to 9 show a third embodiment of the invention, in which the pump head is fixed by means of parts of the cell surrounding the propeller, extending from it and in contact with the wall of the blood vessel.

In FIG. 10-12, a fourth embodiment of the invention is presented in which the pump head is fixed by means of a thread inserted together with a catheter attached to it near the rotor and controlled externally.

The implementation of the invention

In FIG. 1 shows the distal end of a first embodiment of a catheter according to the invention. The head 1 of the pump consists of a cage 2 surrounding the propeller 3 mounted on the drive shaft 4 connected to the drive shaft 5 passing through the elongated sleeve 6. The head 1 of the pump, shown in the working position, is provided with a protruding element 7 intended for insertion into the heart, as shown in FIG. 3.

In FIG. 2 shows the head 1 of the pump during its introduction and the introducer 8. The protruding element 7 is straightened relative to its natural shape (see Fig. 1) and partially inserted into the introducer 8.

In FIG. 3 shows a catheter in the working position in which the protruding element 7 is inserted into the heart 9. Also shown are parts of the vascular system that are important for understanding the operation of the pump:

aortic valve 10;

ascending aorta 11;

arch 12 of the aorta;

carotid arteries 13, 14;

subclavian artery 15;

the descending part 16 of the aorta;

left coronary artery 17;

right coronary artery 18.

Designations 20 and 21 will be explained below.

As shown in FIG. 3, the protruding element 7 has such a length that, when its distal end 7 ′ is abutted against the heart wall 9, the propeller 3 and the cell 2 will be located outside the heart 9, but in the ascending part of the aorta 11, near the aortic valve 10. If by the time the catheter pump is installed the patient’s heart length, to which the protruding element 7 must correspond, is unknown, it can be measured by any suitable method known for this, for example, by heart sounding (see, for example, Vratislav Jonas. Private cardiology. State Publishing House of Copper Zin literature, Prague, 1958, section “Thoracic aortography, heart sounding in CHD”) or two-dimensional echocardiography (see, for example, Schnittger I, Gordon E. P., Fitzgerald PJ, Porr RL Standardized intracardiac measurements of two-dimensional echocardiography, J Am Coll Cardiol., 1983, 2 (5), pp. 934-938). If it is also necessary to determine the size of the ascending aorta, it can also be performed by two-dimensional echocardiography or computed tomography, as well as aortography (see, for example, V.F. Kuznechevsky. Surgical treatment of aneurysms of the ascending aorta. Abstract. M., 2005).

In FIG. 4, 5 and 6 illustrate, in a working position, the distal end of a catheter according to a second embodiment of the invention. Its difference is that the protruding element 7a in its natural (free) state has the shape of a ring, or a part of it, or a spiral, but which can be inserted into the introducer 8 in a straightened state, as shown in FIG. 5. After its introduction, this element takes its original (natural) shape and supports the head 1 of the pump located outside the aortic valve 10. As shown in FIG. 5 and 6, a part of the element 7a in the form of a ring, part of a ring or a spiral is located in a plane perpendicular to the longitudinal axis of the catheter. Moreover, the tip 7a ′ of the distal end of the protruding element 7a in a fixed position is located directly at the proximal edge of the aortic valve, which ensures the positioning of the device according to the invention in the ascending part of the aorta 11.

In FIG. 7, 8 and 9 show a third embodiment of a catheter according to the invention. It is characterized in that some of the tapes, threads or strips 2a are capable of protruding from the cell when deploying from the position of contact with the drive shaft 4 with the formation of the cell in order to contact the wall of the blood vessel, fixing the cell with the propeller enclosed in it in the desired position.

According to a modification based on the same principle, the corresponding threads are fixed on a ring located at the end of the pump head separately from the cage. When a catheter is inserted, these threads are arranged mutually parallel and parallel to the axis of rotation of the pump head. They are made in such a way that in the natural state, after the cell unfolds, they deviate in the radial direction and are fixed to the vessel wall. The advantage of this embodiment is that the threads form a continuation of the pump head in order to avoid an increase in the diameter of the cage.

In FIG. 10, 11 and 12 show a variant of the catheter, which is characterized in that near the head 1 of the pump is fixed thread 19, which is inserted along with the catheter. The thread 19 is controlled from the outside, which allows you to use it to set the position of the pump head 1 in the ascending aorta 11.

Due to the positioning of the pump head 1 in the ascending aorta 11 directly above the aortic valve 10, a retrograde blood flow 20 is created, which increases the blood flow to the left and right coronary arteries 17, 18. At the same time, the normal blood flow 21 created by the pump increases the blood flow to the carotid arteries 13, 14 and subclavian artery 15.

Fixing the pump head in the ascending aorta provides particular advantages, but in some cases it may be useful to fix its position, for example, in the descending branch of the aorta.

Claims (6)

1. A catheter pump for positioning in the ascending part of the aorta (11) near the aortic valve (10) of a human patient, comprising an elongated sleeve (6) with a drive shaft (5) passing through the sleeve and connected with its proximal end to an external source of drive energy, and a rotor, which is installed, from the side of the distal end of the drive rod (5), on the drive shaft (4) connected to the drive rod (5), and is a propeller (3) enclosed in a cage (2) formed by ribbons, threads or stripes, with the ends of the group The indicated tapes, threads or strips are fixed on mutually movable tubes (22) located on the drive shaft (4), and the propeller (3) and the cage (2) are made with the possibility of deployment from a folded position corresponding to the abutment to the drive shaft (4), in the expanded, working position, characterized in that it further comprises means for fixing the rotor (3), after its introduction, in the ascending part of the aorta (11) near the aortic valve (10), which is formed by an element (7) protruding from the distal end of the catheter and intended for heart in the heart (9) in order to use its wall as a support, while the length of the protruding element (7) is chosen such that when the distal end stops against the heart wall, the propeller (3) and the cell (2) are outside the heart, but in the ascending aorta (11) near the aortic valve (10). 2. A pump according to claim 1, characterized in that the tapes, threads or strips of the cell (2) form an open structure that allows the formation of retrograde blood flow outside the rotor. 3. A catheter pump for positioning in the ascending part of the aorta (11) near the aortic valve (10) of a human patient, comprising an elongated sleeve (6) with a drive shaft (5) passing through the sleeve and connected with its proximal end to an external source of drive energy, and a rotor, which is installed, from the side of the distal end of the drive rod (5), on the drive shaft (4) connected to the drive rod (5), and is a propeller (3) enclosed in a cage (2) formed by ribbons, threads or stripes, with the ends of the group The indicated tapes, threads or strips are fixed on mutually movable tubes (22) located on the drive shaft (4), and the propeller (3) and the cage (2) are made with the possibility of deployment from a folded position corresponding to the abutment to the drive shaft (4), in the expanded, working position, characterized in that it further comprises means for fixing the rotor (3), after its introduction, in the ascending part of the aorta (11) near the aortic valve (10), which is formed by an element (7a) protruding from the distal end of the catheter and having in the natural the shape of the ring, part of the ring or spiral, located (located) in a plane perpendicular to the longitudinal axis of the catheter, but made with the possibility of introduction, in a straightened state, into a blood vessel and return to a natural state outside the heart (9) near it with the support of the rotor and placing around the rotor above the aortic valve (10) so that the distal end completing the distal end of the protruding element (7a) is in the wall or close to the wall of the ascending part of the aorta (11). 4. The pump according to claim 3, characterized in that the tapes, threads or strips of the cell (2) form an open structure that allows the formation of retrograde blood flow outside the rotor. 5. A catheter pump for positioning in the ascending part of the aorta (11) near the aortic valve (10) of a human patient, comprising an elongated sleeve (6) with a drive shaft (5) passing through the sleeve and connected with its proximal end to an external source of drive energy, and a rotor, which is installed, from the side of the distal end of the drive rod (5), on the drive shaft (4) connected to the drive rod (5), and is a propeller (3) enclosed in a cage (2) formed by ribbons, threads or stripes, with the ends of the group The indicated tapes, threads or strips are fixed on mutually movable tubes (22) located on the drive shaft (4), and the propeller (3) and the cage (2) are made with the possibility of deployment from a folded position corresponding to the abutment to the drive shaft (4), in the expanded, working position, characterized in that it further comprises means for fixing the rotor (3), after its introduction, in the ascending part of the aorta (11) near the aortic valve (10), some of these tapes, threads or strips or parts thereof ( 2a) are configured to protrusion remove from the cell (2) in order to contact its distal ends with the wall of the blood vessel and fix the cell (2) with the rotor (3) enclosed in it in the ascending part of the aorta (11) near the aortic valve (10). 6. The pump according to claim 5, characterized in that the tapes, threads or strips of the cell (2) form an open structure that allows the formation of retrograde blood flow outside the rotor.

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